<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>类别选择器示例</title>
<style>
.one{
font-family : 实体;
font-size : 40px;
color :red
}
.two{
font-family :实体;
font-size :50px;
color :blue;
}
.three{
font-family :实体;
font-size :11px;
color :green
}

</style>
</head>
<body>
<h2 class ="one">应用了选择器one</h2>
<p>正文内容1</p>
<h2 class = "two">应用选择器two</h2>
<p>正文内容2</p>
<h3 class = " three">应用选择器three</h3>
<p>正文内容3</p>

</body>
</html>